engine SUBARU LEGACY 1996 Service Repair Manual

OBD0513A
10BT2
CHECK INPUT SIGNAL FOR TCM.
1) Connect connector to TCM and CCM.
2) Lift-up the vehicle or set the vehicle on free rollers.
CAUTION:
On AWD models, raise all wheels off ground.
3) Start the engine.
4) Cruise control main switch to ON.
5) TCS OFF switch to ON. (with TCS models only)
6) Move selector lever to“D”and slowly increase vehicle
speed to 50 km/h (31 MPH).
7) Cruise control set switch to ON.
8) Measure voltage between TCM and chassis ground.
: Connector & terminal
(B56) No. 3 (+)—Chassis ground ():
Is the voltage less than 1 V?
: Go to next.
: Check cruise control set circuit. [T7A0].>
: Is there poor contact in TCM connector?
: Repair poor contact in TCM connector.
: Replace TCM.
364
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

BW:—AT/MT IDENTIFICATION CIRCUIT
MALFUNCTION [MT VEHICLES]—
10BW1Check harness between ECM connector and
engine grounding terminal.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

WIRING DIAGRAM:
B2M0617
370
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

B2M0618A
10BW1CHECK HARNESS BETWEEN ECM CON-
NECTOR AND ENGINE GROUNDING
TERMINAL.
1) Turn ignition switch to ON.
2) Measure voltage between ECM and chassis ground.
: Connector & terminal
(B84) No. 81 (+)—Chassis ground ():
Is the voltage more than 2 V?
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between ECM connector and
engine grounding terminal

Poor contact in engine grounding terminal

Poor contact in coupling connector (B22)
: Go to next.
: Is there poor contact in ECM connector?
: Repair poor contact in ECM connector.
: Contact with SOA service.
NOTE:
Inspection by DTM is required, because probable cause is
deterioration of multiple parts.
371
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

G3M0717
3. OPERATION OF SHIFT SELECTOR LEVER
WARNING:
Stop the engine while checking operation of selector
lever.
1) Check that selector lever does not move from“N”to“R”
without pushing the button.
2) Check that selector lever does not move from“R”to“P”
without pushing the button.
3) Check that selector lever does not move from“P”to“R”
without pushing the button.
4) Check that selector lever does not move from“3”to“2”
without pushing the button.
3. Electrical Components Location
1. SENSOR AND CONTROL MODULE
B3M0178B
1Throttle position sensor

2Dropping resistor

3Vehicle speed sensor 2

4Inhibitor switch

5ECM

6Vehicle speed sensor 1 (AWD)

7Vehicle speed sensor 1 (FWD)

8TCM
9Data link connector (for Subaru select monitor only)

10Data link connector (for Subaru select monitor and OBD-II
general scan tool)

11Diagnosis connector

12Diagnosis terminal

13AT OIL TEMP indicator light
(AT diagnostic indicator light)
3
3-2AUTOMATIC TRANSMISSION AND DIFFERENTIAL
2. Pre-inspection - 3. Electrical Components Location

G3M0717
3. OPERATION OF SHIFT SELECTOR LEVER
WARNING:
Stop the engine while checking operation of selector
lever.
1) Check that selector lever does not move from“N”to“R”
without pushing the button.
2) Check that selector lever does not move from“R”to“P”
without pushing the button.
3) Check that selector lever does not move from“P”to“R”
without pushing the button.
4) Check that selector lever does not move from“3”to“2”
without pushing the button.
3. Electrical Components Location
1. SENSOR AND CONTROL MODULE
B3M0178B
1Throttle position sensor

2Dropping resistor

3Vehicle speed sensor 2

4Inhibitor switch

5ECM

6Vehicle speed sensor 1 (AWD)

7Vehicle speed sensor 1 (FWD)

8TCM
9Data link connector (for Subaru select monitor only)

10Data link connector (for Subaru select monitor and OBD-II
general scan tool)

11Diagnosis connector

12Diagnosis terminal

13AT OIL TEMP indicator light
(AT diagnostic indicator light)
3
3-2AUTOMATIC TRANSMISSION AND DIFFERENTIAL
2. Pre-inspection - 3. Electrical Components Location

4. Schematic
B3M0376A
1Ignition switch

2Combination meter

3Speedometer circuit

4Inhibitor switch

5Vehicle speed sensor 2

6Vehicle speed sensor 1

7Throttle position sensor

8Diagnosis switch

9FWD switch (AWD)
10Data link connector

11ABS control module

12Engine speed signal

13Torque control signal

14Torque control cut signal

15Mass air flow signal

16ATF temperature sensor

17Dropping resistor
18Duty solenoid A

19Duty solenoid B

20Duty solenoid C (AWD)

21Shift solenoid 1

22Shift solenoid 2

23Shift solenoid 3

24Brake switch

25Cruise set switch
7
3-2AUTOMATIC TRANSMISSION AND DIFFERENTIAL
4. Schematic

5. Transmission Control Module (TCM)
I/O Signal
OBD0093A
Check with ignition switch ON.
ContentConnector
No.Terminal
No.Measuring conditions Voltage (V)
Back-up power supply B56 14 Ignition switch OFF 10—16
Ignition power supplyB54 6
Ignition switch ON (with engine OFF) 10—16
B55 1
Inhibitor switch“P”range switch B56 9Select lever in“P”range Less than 1
Select lever in any other than“P”
range (except“N”range)More than 8
“N”range switch B56 8Select lever in“N”range Less than 1
Select lever in any other than“N”
range (except“P”range)More than 8
“R”range switch B56 10Select lever in“R”range Less than 1
Select lever in any other than“R”
rangeMore than 6
“D”range switch B54 1Select lever in“D”range Less than 1
Select lever in any other than“D”
rangeMore than 6
“3”range switch B54 2Select lever in“3”range Less than 1
Select lever in any other than“3”
rangeMore than 6
“2”range switch B54 3Select lever in“2”range Less than 1
Select lever in any other than“2”
rangeMore than 6
“1”range switch B54 4Select lever in“1”range Less than 1
Select lever in any other than“1”
rangeMore than 6
Diagnosis switch B56 6Diagnosis connector connected Less than 1
Diagnosis connector disconnected More than 6
Brake switch B56 7Brake pedal depressed. More than 10.5
Brake pedal released. Less than 1
ABS signal B56 5ABS switch ON Less than 1
ABS switch OFF More than 6.5
AT diagnostic signal B55 12Ignition switch ON (With engine OFF) Less than 1
Ignition switch ON (With engine ON) More than 10
8
3-2AUTOMATIC TRANSMISSION AND DIFFERENTIAL
5. Transmission Control Module (TCM) I/O Signal

ContentConnector
No.Terminal
No.Measuring conditionsVoltage
(V)Resistance to
body
(ohms)
Throttle position
sensorB54 8Throttle fully closed. 0.5±0.2
—
Throttle fully open. 4.6±0.3
Throttle position
sensor power
supplyB56 19Ignition switch ON
(With engine OFF)5.05±0.25—
ATF temperature
sensorB54 10ATF temperature 20°C(68°F) 3.45±0.55 2.1—2.9 k
ATF temperature 80°C (176°F) 1.2±0.2 275—375
Vehicle speed
sensor 1B54 12Vehicle stopped. 0
450—720
Vehicle speed at least 20 km/h (12
MPH)More than 1 (AC range)
Vehicle speed
sensor 2B56 11When vehicle is slowly moved at
least 2 meters (7ft).Less than 1)More than 9—
Engine speed
signalB54 5Ignition switch ON (with engine
OFF).More than 10.5
—
Ignition switch ON (with engine ON). 8—11
Cruise set signal B56 3When cruise control is set (SET
lamp ON).Less than 1
—
When cruise control is not set (SET
lamp OFF).More than 6.5
Torque control
signalB55 16 Ignition switch ON 5±1—
Torque control cut
signalB56 16 Ignition switch ON 6—9—
Mass air flow
signalB54 9 Engine idling after warm-up 0.5—1.2—
Shift solenoid 1 B55 141st or 4th gear More than 9
20—32
2nd or 3rd gear Less than 1
Shift solenoid 2 B55 131st or 2nd gear More than 9
20—32
3rd or 4th gear Less than 1
Shift solenoid 3 B55 15Select lever in“N”range (with
throttle fully closed).Less than 1
20—32
Select lever in“D”range (with
throttle fully closed).More than 9
Duty solenoid A B55 8Throttle fully closed (with engine
OFF) after warm-up.1.5—4.0
2.0—4.5
Throttle fully open (with engine
OFF) after warm-up.Less than 1
Dropping resistor B55 7Throttle fully closed (with engine
OFF) after warm-up.More than 8.5
12—18
Throttle fully open (with engine
OFF) after warm-up.Less than 1
Duty solenoid B B55 5When lock up occurs. More than 8.5
9—17
When lock up is released. Less than 0.5
Duty solenoid C
(AWD model only)B55 3Fuse on FWD switch More than 8.5
9—17 Fuse removed from FWD switch
(with throttle fully open and with
select lever in 1st gear).Less than 0.5
Sensor ground
line 1B54 7—0 Less than 1
Sensor ground
line 2B56 20—0 Less than 1
System ground
lineB56 1—0 Less than 1
Power system
ground lineB55 10—0 Less than 1
FWD switch
(AWD model only)B56 2Fuse removed. 6—9.1
—
Fuse installed. Less than 1
9
3-2AUTOMATIC TRANSMISSION AND DIFFERENTIAL
5. Transmission Control Module (TCM) I/O Signal

B: ABNORMAL DISPLAY ON AT OIL TEMP
INDICATOR
When any on-board diagnostic item is malfunctioning, the
display on the AT OIL TEMP indicator blinks immediately
after the engine starts.
The malfunctioning part or unit can be determined by a
trouble code during on-board diagnostic operation. Prob-
lems which occurred previously can also be identified
through the memory function.
If the AT OIL TEMP indicator does not show a problem
(although a problem is occurring), the problem can be
determined by checking the performance characteristics of
each sensor using the select monitor.
Indicator signal is as shown in the figure.
WARNING:
Warning can be noticed only when the engine is ini-
tially started.
B3M0410A
11
3-2AUTOMATIC TRANSMISSION AND DIFFERENTIAL
6. Diagnostic Chart for On-board Diagnostic System

D: LIST OF TROUBLE CODE
1. TROUBLE CODE
Trouble code Item Content of diagnosisAbbr.
(Select monitor)Page
11 Duty solenoid ADetects open or shorted drive
circuit, as well as valve seizure.PLDTY 15
12 Duty solenoid BDetects open or shorted drive
circuit, as well as valve seizure.LUDTY 19
13 Shift solenoid 3Detects open or shorted drive
circuit, as well as valve seizure.OVR 23
14 Shift solenoid 2Detects open or shorted drive
circuit, as well as valve seizure.SFT2 25
15 Shift solenoid 1Detects open or shorted drive
circuit, as well as valve seizure.SFT1 27
21 ATF temperature sensorDetects open or shorted input
signal circuit.ATFT 29
22 Mass air flow signalDetects open or shorted input
signal circuit.AFM 32
23 Engine speed signalDetects open or shorted input
signal circuit.EREV 34
24 Duty solenoid CDetects open or shorted drive
circuit, as well as valve seizure.4WDTY 36
25 Torque control signalDetects open or shorted input
signal circuit.TQ.CT 38
31 Throttle position sensorDetects open or shorted input
signal circuit.THV 40
32 Vehicle speed sensor 1Detects open or shorted input
signal circuit.VSP1 43
33 Vehicle speed sensor 2Detects open or shorted input
signal circuit.VSP2 47
13
3-2AUTOMATIC TRANSMISSION AND DIFFERENTIAL
6. Diagnostic Chart for On-board Diagnostic System